From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Difficulties and a proposed scheme for extra cylinder lubrication.
| Identifier | ExFiles\Box 14\3\ Scan038 | |
| Date | 3rd September 1929 | |
| To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to SS.{S. Smith} Hs.{Lord Ernest Hives - Chair} c. to EP.{G. Eric Platford - Chief Quality Engineer} x7050 Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}1/MJ.3.9.29. For Sketch see original. S.S. EXTRA CYLINDER LUBRICATION. -------------------- "With reference to E1/MS.7.29., there are one or two difficulties in the scheme you outline. On the present relief valve, though we have a considerable rise of pressure with speed, it is necessary to run the engine at 1750 r.p.m. to ensure 45 lbs/sq.in. main oil pressure. If the relief valve is restricted to give this pressure at the slow running speed of the engine, say 500 r.p.m., the gauge is almost certain to be smashed if the car is speeded up when cold. If the extra oil is only arranged to come in when the engine is run fast, the considerate owner who warms up at rational speeds will not get any extra oil on his pistons. A scheme we have rigged up temporarily works from the starter carburetter. Each time this is operated, a valve opens and admits main oil pressure to jets in the cylinder walls. When the starter carburetter is turned off the valve closes slowly. The closing of the valve is controlled by an oil dash-pot. When the engine is very cold, the valve remains open for 10 mins. When hot for 30 secs. only, as the temp. of the oil in the dash-pot dictates the time of closing. This appears to be reasonably fool proof, as the driver cannot over-oil his engine unless he keeps the starter carburetter open continuously. | ||